Tetrakisazo dyestuffs



2,960,497 Patented 'Nov. 15, I960 "ice wherein R means hydrogen or a methyl group with 2,5- 60,497 diaminobenzene-l-carboxylic acid in a sodium-alkaline TETRAKISAZODYESTUFFS medium with the formation of a second azo. grouping.

'The'new dyestuffs are excellently suitable for the dye- Ernst Messmer, Leverkusen, Germany, assignor to Far- 5 ing of cotton and regenerated cellulose and yield on benfabl'lkell Aktiengseuschafi, Levefkllsell, these materials preponderantly black dyeings of very good many, acorporation of Germany fastness properties, particularly a very good fastness to N0 Drawing. Filed A'ug. 3,1959, Ser. N0.831,058 Wetting light- The following examples are given for the purpose of Claims priority, apphcatlon Germany Aug. 12, 1958 10 illustrating the invention.

1 Claim. (Cl. 260-'157) Example 1 The present invention is directed to new metallizable 38.1 parts by weight of the disodium salt of 4-aminoazo dyestuifsgrnoreparticularly it relates to tetrakisazo 4'-hydroxy-3-carboxybenzene-azo-(1,1) benzene-Z-suldyestufis of the formula fonic acid are dissolved in about 300 parts by volume R R H0 H00 0 R1 R3 H038 NH2 ln'this formula R means hydrogemora methyl group, of water and diazotized indirectly in hydrochloric acid R stands for hydrogen or a sulfonic acid group, R :at about'15 -C. with 6.9 parts by weight of sodium denotes a methoxy or a carboxylic acid group, R means nitrite. Into the pale brownish yellow suspension of hydrogen, methyl or methoxy andRgstandsfor 'hydrothe diazo compound there is stirred with the simulgen ormethyl, with the 'provisionthat fR 'ls methoxy taneous addition of ice a hydrochloric acid solution of when R stands for a sulfonic acid group. 14 parts by weight of 3-amino-4-methoxy-l-methylben- The new metallizable tetrakisazo dyestufis can be con- 'zene, and the mixtureds kept just neutral to Congo by veniently prepared 1 by diazotizing 4-aminobenztriazole the-addition=of'sodimnacetate. "After completion of the which may be substituted in the benzene nucleus by a coupling, the disazo dyestufi thus formed is isolated alrnethyl group, coupling with Z-amino-S-hydroxynaph- 40 kaline.

thalene-7-sulfonic acid in an acid medium and subse- In a separate mixture 17 parts by weight of the hyquently reacting the monoazo compound thus obtained drochloride of 4-aminobenztriazole are dissolved in about in an alkaline medium with the diazo compound of an 200 parts by volume of water and treated with good amino-disazo compound having the formula stirring in rapid sequence with ice, parts of concen- R 1% 45 trated hydrochloric acid and a concentrated solution of 6.9 parts by weight of sodium nitrite.

HO- N=N N=N NH; The diazo solution thus obtained, kept cold and, if necessary, filtered, is builered with 23 parts by weight HOOC R1 R3 of sodium acetate and gradually treated with a weakly wherein R, R R and R have the same meaning as acetic acid solution of 26 parts by weight of the sodium indicated above. salt of Z-amino-S-hydroxynaphthalene-7-sulfonic acid in The amino-disazo compound used for coupling in the about 200 parts by volume of Water. Coupling proalkaline range is obtained in various ways depending on ceeds fairly rapidly, even while the mixture still shows the substitution, for example by diazotizing 1-nitro-4- a marked acid reaction to Congo. The red monoazo aminobenZene-3-sulfonic acid, coupling with salicylic dyestuff thus formed is precipitated soda-alkaline with acid which may be substituted by a methyl group, resodium chloride and isolated. ducing in the nitromonoazo dyestuif the nitro group to The disazo dyestuff obtained by the process described the amino group, diazotizing again, and coupling with above is dissolved as highly concentrated as possible in 1-amino-2,5-dialkoxybenzene or 1-amino-2-alkoXy-5-alhot water and the solution is filtered through animal kylbenzene in the p-position to the amino group. charcoal. In the filtrate which after cooling is a copper- Amino-disazo compounds of the above mentioned type colored suspension, the aminodisazo compound is diwhich in the o-position to the diazotizable amino group azotized with 6.9 parts by weight of sodium nitrite and contain a carboxylic acid group instead of the alkoxy the requisite amount of hydrochloric acid at about 15 substituent, can be produced by the process of US. C., whereupon the color turns via black to brown. The patent specification No. 2,109,183 by condensing the paste of the red monoazo dyestuff is dissolved with 30 nitromonoazo dyestufi' obtainable according to the procparts by weight of sodium carbonate, parts by weight ess described above and having the formula of pyridine and about parts by volume of water;

R the solution is stirred with the brown diazo suspension while cooling with ice. The deep black colored mixture H0 N=NC NOB 70 which forms a thick paste becomes more thinly liquid after prolonged stirring. For isolation of the tetrakisazo B000 1 dyestufi, the mixture is heated to 70-80 C. and stirred 3 4 with about 7.5 percent of sodium chloride. The dyetainable by sodium-alkaline condensation of 4-nitro-4- stuflf filtered oflf with suction from the liquor is black, hydroxyazo-benzene-3-carboxylic acid with 2,5-diaminodissolves in water with a blue, in concentrated sulfuric benzene-carboxylic acid, are stirred in about 300 parts acid with a greenish grey color; the after-coppered dyeby volume of Water and diazotized indirectly in hydroing on cotton is greyish blue to deep blue-black, de- 5 chloric acid with 6.9 parts by weight of sodium nitrite pending on the intensity, and is distinguished by a very below 20 C. The diazo compound is combined in the good fastness to light and wetting. same manner as described in Example 1 with the mono- Dyestufis of similar dyeing properties are obtainable azo 'dyestufif obtained by acid coupling of diazotized by the same .methed when using 39.5 parts by Weight 4-an1inobenztriazole with 2-amino-fi-hydroxynaphthaleneof the disodium salt of 4-amino-4-hydroXy-3'-carboXy- 10 7-sulfon-ic acid. The isolated tetrakisazo dyestuflf is a 5' or -6'-methylazo-(l,l')-benzene-2-sulfonic acid inblack powder and issolves in water with a violetish gray, stead of 38.1 parts by weight of the above mentioned in concentrated sulfuric acid with a clear greenish blue starting component, or 18.4 parts by weight of 4-aminocolor. The after-coppered dyeing on cotton is bluish 7-methy1benztriazole hydrochloride instead of 17 parts black and very fast to light and wetting. by weight of -4-aminobenztriazole hydrochloride. 15 I claim:

If instead of the 14 parts by weight of 3-amino-4- A metallizable tetrakisazo dyestufi of the formula R 1'12 lilo 110- N: QN=NQN=N HOOC J R R3 H015 NH;

N R N/ methoxy-l-methylbenzene 16 parts by Weight of Z-aminowherein R stands for a radical selected from the group 1,4-dimethoxybenzene are applied in the procedure deconsisting of hydrogen and methyl, R means a member scribed in the first paragraph of this example, a dye: selected from the group consisting of hydrogen and a stuff is obtained which dissolves in water with a clear 35 sulfonic acid group, R stands for a member selected blue, in concentrated sulfuric acid with a greyish blue from the group consisting of methoxy and a carboxylic color. The after-coppered dyeing on cotton is greyish acid group, R being methoxy when R stands for a sulblue to blue-black showing a somewhat greener shade. fonic acid group, R means a substituent selected from the group consisting of hydrogen, methyl and methoxy, 0 and R stands for a radical selected from the group con- 44.9 parts by WElgllt Of the dlSOdlUIIl salt Of the (115310 isting of hydrggen and methyL dyestulf 4-amine-3-carboxybenzene-azo-(1,4) benzene- 8Z0(1',1"')-4"-hYdI'OXYb6i1ZBI1-3"-CfllbOXYllC acid, 011- 7N0 references cited.

Example 2 

